standards / manuals / guidelines for small hydro development - AHEC

2.3 PREDICTIVE MAINTENANCEThis sort maintenance ensures ability to judge when a piece of equipment is going to fail andreplace the same before it does. Usually it requires some form of testing and analysis whichhelps predict an eminent failure. Predictive maintenance can be used in conjunction withpreventive maintenance practices. In hydro power station there are many monitoringsystems, which can be used to predict problems and possible failures. These includevibration monitoring, oil analysis, temperature, systems ampere readings resistance readingsof motors, efficiency in power generation out put, leakages of oil and water. All of thesethings can be captured and tracked by computer system. The analysis of data can predict thefuture.2.4 PROACTIVE MAINTENANCEMost recent innovative in maintenance is called proactive and it utilizes a technique called“root cause failure analysis”. In this type of maintenance primary cause of failure is soughtand corrected.2.5 RELIABILITY CENTERED MAINTENANCE (RCM)This sort of maintenance is defined as “a process used to determine the maintenancerequirements of any physical asset in its operating context”. It is an on going process whichdetermine the mix of reactive preventive and proactive maintenance practices to providereliability at the minimum cost. It recognises that all equipments in facility are not of equalimportance for generation as well as plant safety. It recognizes that design and operation ofeach equipment differs and therefore, possibility of failure also differs from equipment toequipment. In this system diagnostic tools and measurements are used to assess when acomponent is near failure and should be replaced. In this approach basic thrust is to eliminatemore costly unscheduled maintenance and to minimize preventive maintenance. In thissystem unimportant maintenance activities are left to reactive maintenance approach.3.0 REQUIREMENT OF EFFECTIVE MAINTENANCEIn addition to planning maintenance and allotting suitable time interval on the basis of watersupply availability following items also require close watch otherwise it may become difficultto adhere to the schedules.i) Man power planning and arrangement is most essential as without experienced /skilled staff any maintenance programme may fall.ii) Planning and arrangement of spares and consumable in advance so that time is notlost I arrangement of the same after taking shut down.iii) The maintenance engineers should have in his possession al the erection andcommissioning log sheet document to establish a record of installed clearances,parameters, alignment results, test characteristics of al the power plant equipment.These may be required at the time o diagnosis of the operational problems as well asdefined maintenance purpose.iv) Log sheets of the previous maintenance exercise carried out on the machines. Thesemay be required to compare with the clearances/ settings/characteristics achievedduring present maintenance.AHEC/MNRE/SHP Standards/ E&M Works – Guidelines for Operation and Maintenance of Small Hydropower Station 16